Sonic Hedgehog pathway
Sonic Hedgehog pathway is one of the complex signal transduction mechanism that controls or governs the process of cellular development.
The Hedgehog signaling pathway plays a critical role in the morphogenesis during embryogenesis.
PTCH(patched) gene is a tumour suppressor gene
In “off” state the PTCH exists in complex with another transmembrane protein called SMO(smoothened) which prevents SMO to activate GLI-1( Glioma associated Oncogene 1) proteins and thus cell division
Pathogenesis of several tumours involves mutations in PTCH (patched) gene, a tumour suppression gene which results in uncontrolled activation of Hedgehog pathway signaling.
Loss of PTCH function, results in constitutive activation of SMO and GLI-1 resulting in unregulated cell division and abnormal growth.
Loss-of-function mutations within this Sonic Hedgehog pathwayresults in holoprosencephaly
Tumours known to have occurred through this pathway are
a. Basal cell carcinoma,
b. medulloblastoma
c. pancreatic carcinomas
CLICK HERE to read Pathology of Basal cell carcinoma
